Extruded

Heat Sinks

All other products, please contact factory for price, delivery, and minimums.

Normally stocked

52

EXTRUDED HEAT SINKS FOR POWER SEMICONDUCTORS

431 AND 433 SERIES

High-Performance Heat Sinks for 30-100W Metal Power Semiconductors

Need maximum heat dissipation from a TO-3 rectifier heat sink in

minimum space? The Wakefield 431 and 433 Series center chan-

nel double-surface heat sinks offer the highest performance-to-weight ratio for minimum vol-

ume occupied for TO-3, diode, and stud-mount metal power semiconductors in the 30- to

100-watt operating range. Additional interface resistance reduction for maximized overall per-

formance can be achieved with proper application of Wakefield Type 126 silicone-free thermal

compound. Material: Aluminum Alloy, Black Anodized.

TO-3; Stud-Mount

TO-3

Nominal Dimensions

Standard

Width

Length “A”

Height

Semiconductor

Thermal Performance at Typical Load

Weight

P/N

in. (mm)

in. (mm)

in. (mm)

Mounting Hole Pattern Natural Convection

Forced Convection

lbs. (grams)

431K

4.750 (120.7)

3.000 (76.2)

3.000 (76.2)

None

55°C @ 5OW

0.40°C/W @ 250 LFM

0.7800 (353.81)

433K

4.750 (120.7)

5.500 (139.7)

3.000 (76.2)

None

42°C @ 5OW

0.28°C/W @ 250 LFM

1.4900 (675.86)

Dimensions: in. (mm)

MECHANICAL DIMENSIONS

SERIES

431

433

K

NATURAL AND FORCED

CONVECTION CHARACTERISTICS

SEMICONDUCTOR

MOUNTING HOLE

431 AND 433

SERIES

(EXTRUSION

PROFILE 2726)

435 SERIES

Lightweight Quadruple Mount Heat Sink for TO-3 Case Styles

Nominal Dimensions

Standard

Width

Length

Height

Semiconductor

Thermal Performance at Typical Load

Weight

P/N

in. (mm)

in. (mm)

in. (mm)

Mounting Hole Pattern Natural Convection

Forced Convection

lbs. (grams)

435AAAA

4.250(108.0)

5.500(139.7)

4.300(109.2)

(4) TO-3

37°C @ 50W

0.38°C/W @ 250 LFM

1.1500 (521.64)

54°C @ 80W

0.24°C/W @ 600 LFM

MECHANICAL DIMENSIONS

Dimensions: in. (mm)

NATURAL AND FORCED

CONVECTION CHARACTERISTICS

SEMICONDUCTOR

MOUNTING HOLES

AAAA

441 SERIES

High-Performance Natural Convection Heat Sinks for Rectifiers and Diodes

Stud-Mount

Nominal Dimensions

Standard

Width

Length

Height

Semiconductor

Thermal Performance at Typical Load

Weight

P/N

in. (mm)

in. (mm)

in. (mm)

Mounting Hole Pattern

Natural Convection

Forced Convection

lbs. (grams)

441K

4.750 (120.7) 5.500 (139.7) 4.500 (114.3)

None

34°C @ SOW

0.30°C/W @ 250 LFM

1.9700 (893.59)

47°C @ 80W

0.19°C/W @ 600 LFM

Designed for vertical mounting within a power supply enclosure

or equipment cabinet without forced airflow available. This

Wakefield 441 Series heat sink will dissipate up to 100 watts efficiently in natural convection

with a maximum 55°C heat sink temperature rise above ambient. When applied in a forced

convection environment, the 441K Type will achieve thermal resistance of 0.18°C/W (sink to

ambient) at 1000 LFM. Supplied with no predrilled device mounting hole pattern. Material:

Aluminum Alloy, Black Anodized.

This lightweight high-performance heat sink is designed to

mount and cool efficiently one to four TO-3 style metal case

power semiconductors. The Type 435AAAA is the standard configuration available from stock,

predrilled for mounting four TO-3 style devices. Increased performance can be achieved with

the proper selection and installation of a Wakefield Type 175 DeltaPad Kapton™ interface

material for each power semiconductor or, for maximum reduction of case-to-sink interface

loss, the application of Wakefield Type 126 silicone-free thermal compound. Material:

Aluminum Alloy, Black Anodized.

435 SERIES

(EXTRUSION

PROFILE 4226)

MECHANICAL DIMENSIONS

NATURAL AND FORCED

CONVECTION CHARACTERISTICS

SEMICONDUCTOR

MOUNTING HOLE

441 SERIES

(EXTRUSION

PROFILE 1273)

K

Dimensions: in. (mm)